Minor fix to protobuf parser's nextFieldName() impl (when skipping unknown field ids)

Author: cowtowncoder

protobuf/src/main/java/com/fasterxml/jackson/dataformat/protobuf/ProtobufParser.java

@@ -1083,9 +1083,9 @@ public String nextFieldName() throws IOException
 
             ProtobufField f = _findField(id);
             if (f == null) {
-                _skipUnknownField(id, wireType);
-                // may or may not match, but let caller figure it out
-                return null;
+                if (_skipUnknownField(id, wireType) != JsonToken.FIELD_NAME) {
+                    return null;
+                }
             }
             String name = _currentField.name;
             _parsingContext.setCurrentName(name);

release-notes/VERSION

@@ -15,6 +15,7 @@ Modules:
  (contributed by philipa@github)
 #116: (protobuf) Should skip the positive byte which is the last byte of an varint
  (contributed by marsqing@github)
+- (protobuf) Minor fix to skipping with `nextFieldName()`
 
 2.9.2 (14-Oct-2017)